SAN FRANCISCO, Calif. -- An inexpensive new treatment for hepatitis C,
a disease that afflicts 1-2 percent of the population, is more effective
than the standard therapy, according to a recent study.
The pilot study, recently completed at Penn State's Milton S. Hershey Medical
Center, treated patients with amantadine, a drug that has been available
in the United States since the 1960s. Thirty percent of the patients in
the study responded to amantadine treatment.
Amantadine costs only $20 per month -- a tiny fraction of the cost of interferon,
the conventional treatment for hepatitis C. Interferon costs approximately
$500 per month, and must be administered for at least six months.
Jill P. Smith, M.D., associate professor of medicine at Hershey, discovered
that amantadine is an effective alternative treatment for hepatitis C --
without the extensive side effects associated with interferon. Smith will
present the results of her study on May 19 at San Francisco's Mosconi Convention
Center as part of the annual meeting of the American Gastroenterological
Association and the American Association for the Study of Liver Diseases.
Interferon's frequent side effects include a drop in white blood cell count
and flu-like syndrome with aches, pains and fever. Hair loss, anemia, thyroid
disease and severe depression occur less frequently.
Amantadine has fewer side effects, including: difficulty in concentration,
constipation and rare cardiac symptoms in some elderly patients. Another
drawback of interferon treatment is that only 50 percent of the patients
respond to it, according to Smith. Half of those responders relapse after
they stop the six months of therapy, dropping the effectiveness rate to
approximately 25 percent.
The poor response, side effects and cost of interferon treatment prompted
Smith to look for another drug.
Smith's study included 22 patients who were monitored over a four-year period.
Only those who failed treatment with interferon were allowed into the study.
As a control the same group of patients were monitored during two intervals
of no treatment.
Patients received 100 milligrams twice a day. "We know this is a safe
dose," said Smith.
Of the 22 patients, 20 completed the study and two dropped out due to chest
pains and shortness of breath. Six of the 20 responded to treatment, 8 had
a partial response, and 6 did not respond to amantadine.
"If we used a higher dose, or treated longer, it's possible the partial
responders would have responded completely," said Smith.
She said the response to treatment might have been greater with a group
of patients who had never been treated with interferon, since her study
only treated those with interferon-resistant disease.
"We need support for further studies," said Smith. "It would
be nice to have a multicenter control, making amantadine available to people
across the country who have hepatitis C.
"There was no drug company support for this study," said Smith.
"Most patients paid, luckily it was inexpensive."
She noted another benefit of amandatine -- it can be taken orally, instead
of by injection, which is the only way to administer interferon. Interferon
is usually self-administered, a drawback, according to Smith because "a
lot of hepatitis C patients are former drug users and don't want to have
anything to do with needles. Also contaminated needles are a threat to other
household members."
Hepatitis C was only isolated and identified as a virus in 1989. Frequently
those carrying the disease are unaware of it until they develop cirrhosis
of the liver.
"Most people are asymptomatic," said Smith. "A lot find out
when they go to donate blood."
Chronic fatigue may be the only symptom, according to Smith.
There are two primary ways that hepatitis C is transmitted. They are: transfusions
with tainted blood, and contact with contaminated needles by IV drug users.
Most of the tainted blood transfusions occurred before 1989 when blood banks
began testing for hepatitis C.
"There's a lot we don't understand about the epidemiology of hepatitis
C," said Smith. "Thirty to 40 percent of the patients don't know
where or how they got the disease."